package jdbc;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;

public class JDBCDemo6 {
    public static void main(String[] args) {
        try(
                Connection connection = DBUtil.getConnection()
        ) {
            Statement statement = connection.createStatement();
            String sql = "SELECT COUNT(*) count " +
                    "FROM class c " +
                    "JOIN student s ON c.id = s.class_id " +
                    "WHERE c.name = '1年级1班'";
            ResultSet rs = statement.executeQuery(sql);
            while(rs.next()){
                int count = rs.getInt("count");
                System.out.println("人数:" + count);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
